中文摘要：

汶川地震后,强震作用下的大坝混凝土动态力学性能研究广受关注。本文利用CT技术对动力荷载作用下混凝土细观破裂过程进行实时扫描观测,获得了混凝土试件在动力荷载作用下裂纹的开裂、扩展、贯通的全过程CT图像,并给出了动力压缩、动力拉伸CT试验的初步成果。结果表明：动力压缩荷载条件下混凝土破坏时裂纹起裂点多,裂纹演化速度快,能够解释其动态强度提高的原因;而动力拉伸荷载条件下破裂面较平整,当加载速率较高时,裂纹穿越骨料非常明显。该研究为探索混凝土材料在动力荷载作用下的损伤演化规律提供新的研究途径。

英文摘要：

After the Wenchuan Earthquake,the dynamic behavior of concrete dams subjected to strong earthquake is widely paid attention to.The real time scanning observation of meso fracture in concrete under dynamic load is carried out by means of CT technology,so the CT image of crack propagation,coalescence and failure is obtained in the whole process under dynamic compression and the preliminary dynamic compression and tension results of concrete by CT are given.Based on all these analyses,when the concrete is to be failure,the crack points are increased and the crack evolution velocity is high.It is one of the reasons to make concrete dynamic strengths increase.Meanwhile,when the loading rate is higher,the crack will cut through the aggregate obviouly and the failure plane is relatively smooth under dynamic tension.It will put forward some new ideas to the study of dynamic behavior and damage law of concrete material under dynamic loading.